RIP USS Thresher

[Bilge_Rat]

yes waking up this thread after 14 years since new info has been coming out on what caused the loss of USS Thresher.

https://www.popularmechanics.com/mil...ied-documents/

Following a successful lawsuit by retired Capt. James Bryant, the U.S. Navy has been forced to release the entire 1700 pages report on the sinking which was still confidential.

The official version was that a burst water pipe at depth had caused uncontrollable flooding which lead to the loss of the sub.

An alternative theory had been put forward by Bruce Rule in 2013 which is detailed here:

http://www.designed4submariners.com/...rpion_Loss.pdf

Basically according to SOSUS data analysed by mr. Rule:

1. While cruising "deep", around 1300 feet, Thresher had a short circuit which caused the reactors to shut down.

2. Due to the pressure and design faults, the compressed air was unable to blow the MBT (basically ice built up which blocked the air so the MBTs remained full of water); and

3. the crew scrambled to restart the reactors, but the sub drifted down way past its crush depth before this could be done.

This was an interesting theory, but new info has been coming out which gives it more weight:

1. Bruce Rule was a SOSUS technician way back in 1963 and he had analysed the data at that time on which he based his report;

2. mr. Rule testifed on this at the inquiry on the loss, but a lot of pressure was put on him to change his testimony and on members of the inquiry to not adopt his theory as the official cause.

The inquiry reported that the Thresher’s MCPs had stopped, which would have caused an automatic reactor shutdown (scram) or a shift to slow speed. While Rule was positive the MCPs stopped, Naval Reactors said the acoustic data were inconclusive.6 Two commanders—not members of the Naval Court of Inquiry and likely acting as agents for Naval Reactors—tried to intimidate Rule during his classified testimony before the court into saying that the MCPs were in slow speed, not fast. Slow-speed MCPs were a more reliable lineup, but Ronald Estes, a reactor operator who served 14 months on the Thresher, recalls that it was normal to run fast-peed MCPs during deep dives to ensure immediate availability of flank speed to go shallow.

In a 1987 interview with Fred Korth, Secretary of the Navy when the Thresher was lost, and his executive assistant, Vice Admiral Marmaduke Bayne, both said Rickover had altered portions of the Naval Court of Inquiry’s report, and had probably done so because wording on MCPs was left as “inconclusive.”7 This deflected blame for the sinking away from Naval Reactors by creating doubt that there had been a scram.

https://www.usni.org/magazines/proce...-thresher-data

My own interpretation is that Adm. Rickover did not want any part of the loss to be blamed on the nuclear reactors which would have shaken confidence in their safety.

[Mr Quatro]

It was a terrible tragedy, but after 58 years just think of all the lives the investigation of what caused the accident have saved.

I think they call it 'Sub Safe"

[FireDragon76]

In both the case of the USS Thresher and USS Scorpion, the subs were lost because the emergency system used to blow ballast wasn't up to the task of diving to those depths. There was freezing in the system due to the extreme pressures they were working under.



Sub Brief on Youtube has good analysis of the loss of both boats, going into the details of the likely reasons they were lost.


The possibility cannot be denied that Rickover might have tried to downplay the safety risks of having a single nuclear reactor on a submarine as the sole means of propulsion. Soviets often would use two reactors on their early nuclear boats for this reason alone, and on some of their single-reactor designs, they would either use backup electric motors or they would use highly reactive metals to produce gas to blow out the ballast. Of course, Soviets were often trading off noise for deep diving and survivability as a result.

[ETR3(SS)]

Originally Posted by FireDragon76

In both the case of the USS Thresher and USS Scorpion, the subs were lost because the emergency system used to blow ballast wasn't up to the task of diving to those depths.

Both Scorpion and Thresher were operating within their submerged operating envelope, meaning the EMBT Blow system was rated for the depth they were at when their respective accidents occurred.

There was freezing in the system due to the extreme pressures they were working under.

There was freezing in the system due to the presence of moisture in the compressed air used for the EMBT system. When the valves were opened releasing that compressed air, the pressure dropped and in turn caused the air temperature to drop. The lower temperatures caused the moisture to condense on the piping until it got cold enough to freeze, blocking the piping.

The possibility cannot be denied that Rickover might have tried to downplay the safety risks of having a single nuclear reactor on a submarine as the sole means of propulsion. Soviets often would use two reactors on their early nuclear boats for this reason alone, and on some of their single-reactor designs, they would either use backup electric motors or they would use highly reactive metals to produce gas to blow out the ballast. Of course, Soviets were often trading off noise for deep diving and survivability as a result.

The reactor is not the sole means of propulsion. An Emergency Propulsion Motor can be clutched in to the shaft to provide emergency propulsion should the reactor shut down. Not sure where you're getting this idea of safety risks involved with a single reactor design. The USN has had ZERO reactor incidents with its single or dual reactor designs. All the reactors in the world don't matter if you have a steam line rupture and have to shut your Main Steam valves.

[Marko_Ramius]

Some news ; more tragedy to the tragedy :

[CJMars]

Jesus. Cheers to those on eternal patrol. 07

[Catfish]

I 'found' this Sub Brief channel when Kapitan posted a critic of the french film "The Wolf's call", lot of interesting videos by him.

^ Then today i found this posted above, only recently released material on july 13th 2021(?), almost 60 years later. This is so .. bad.
Fair winds and following seas to the crew.

[Mr Quatro]

It's just click bait my friends ...

At the depth she sank she imploded the power was not available for sonar to ping.

Let her rest in peace

[Texas Red]

I actually had tears in my eyes.

I pray that the Lord bring closure and justice to the families of the men aboard the USS Thresher. They have the right to learn what exactly happened there.

And Mr. Quatro: if you watched the video it said that the boat hovered just above crush depth and below test depth. She still had power to give off pings.

[Catfish]

^ That, and also almost tears.
I am not aggravated or anything that the Navy did not tell it back then, possible causes and explanations also being spoken of in the video.

Originally Posted by Mr Quatro

It's just click bait my friends ...
At the depth she sank she imploded the power was not available for sonar to ping.Let her rest in peace

Obviously it was not so. The material being discussed in the video by "Sub Brief" has only been declassified now in july 2021.
Thresher seems to have been hovering above crush depth for two days, with part of the crew being able to communicate, sending out those 37 pings before the battery probably failed, later banging on the hull. Trying to surface or at least hold the boat without a working reactor. Until the batteries were empty, cold, and lack of oxygen sealed its fate. It seems it was without propulsion, slowly circling deeper below crush depth until it imploded after more than 48 hours. This is an absolutely gruesome situation. And nothing could be done to save boat or crew. Not that much could be done today in such a situation.

And this is the point: There should be learned something of what happened, "letting something rest in peace" maybe ok for the diseased crew (though i doubt they would see things that way), but it is absolutely necessary to analyse what happened, to improve rescue actions in the future.

In case of the Thresher and a similar situation today, there still would be no chance to rescue, because such a scenario has never been thought of. I doubt they would be even able to get an exact position and guide a DSRV to a hovering boat, when you cannot even communicate without going to PD or surface.

DSRV vehicles somehow always manage to come too late for whatever reason, communication cut, intel security/secrecy reasons, or sheer distance and time to get to the position of rescue needed.
Which can be called negligence, active cover up or deception, which is too often convenient to divert from deficits, and evading and getting rid of witnesses.
When the DSRV manages to come near a docking may be impossible because the sub is not lying on even keel or rolled a bit to either side, the angle of the emergency escape hatch making the docking impossible.

And there is still not much that you can do with the current state of emergency rescue facilities. There are much too few DSRVs, if you need days to reach a submarine in trouble this is only a pretense of being able to help.
The emergency rescue "program" for military submarines is lacking so much that it is virtually inexistent. When your sub gets in trouble and you cannot fix it as a crew, you are toast. Then, and now.

[Mr Quatro]

Originally Posted by El Whacko

I actually had tears in my eyes.

I pray that the Lord bring closure and justice to the families of the men aboard the USS Thresher. They have the right to learn what exactly happened there.

And Mr. Quatro: if you watched the video it said that the boat hovered just above crush depth and below test depth. She still had power to give off pings.

That is simply not possible ... this is still click bait

[Mr Quatro]

Originally Posted by Catfish

Thresher seems to have been hovering above crush depth for two days, with part of the crew being able to communicate, sending out those 37 pings before the battery probably failed, later banging on the hull. Trying to surface or at least hold the boat without a working reactor. Until the batteries were empty, cold, and lack of oxygen sealed its fate.

The pings were from other ships and even one submarine near by ... submarines don't ping they certainly have the ability to go active, but they never do and when they do the transducer take so much energy that they would not I repeat they would not send just 37 pings.

[Dowly]

Someone over at r/submarines explained Sea Brief (and his video) as follows:

I will say it again. Aaron Amick is a ****ing dis-owned in the SONAR community hack who does this surely for clicks and impressions. He knows diddily **** about submarine operations and should stop opening old wounds in the families that have already made peace with this.

Seriously though, a sound that fit that of an implosion was heard on the 10th. No such sounds were registered during the wider search even with so many vessels present.

[Catfish]

If SOSUS picked up the implosion on the tenth a survival would be unlikely. Did they record an implosion at that date, and if. is it sure it was the T.?

https://www.thedrive.com/the-war-zon...jKP52SuDoRqBaE

There remains some doubt, seems portions of the initial report had been altered by Rickover, but admittedly it is only about some seconds or minutes shifted in the events, no date or other major changes.

And reading this* i would doubt the new video of the T. having survived the tenth. The article below clearly states that propulsion, mbt vents and all kinds of machinery sounds had been heard from surface ships and SOSUS at exact times, until the collapse of the hull.
* https://www.usni.org/magazines/proce...-thresher-data

But what did the Seawolf hear then? Garbled Gertrude voices surely not from surface ships, but especially an active sonar which frequency fits to the Thresher's hull sonar but not to surface ships. Hull clanging noises after requesting. The Seawolf's hydrophones and active sonar were beneath the thermal layer, also its sonar echo stopping when running above the "object" dead in the water and appx a 150 feet deeper indicates there was something. Even the orientation of this object makes sense.

This seems to be the last published report, 600 pages pdf.
https://news.usni.org/2021/07/09/nav...uiry-documents

[Dowly]

Originally Posted by Catfish

If SOSUS picked up the implosion on the tenth a survival would be unlikely. Did they record an implosion at that date, and if. is it sure it was the T.?

I'll let someone more knowledgeable than me answer that:

I am the only person living or now dead who ever analyzed the SOSUS detections
of the loss of THRESHER. I provided the results of that analysis to the Naval Court
of Inquiry on 18 April 1963.

The THRESHER pressure-hull imploded at 09:18:24 ROMEO Time Zone on
10 April 1963 at a depth of 2400-feet with an energy released equal to the
explosion of 22,500 pounds of TNT at that depth. The crew died in less than
47 milliseconds. Minimum time required for human recognition of an event is
80-100 milliseconds.

Bruce Rule


**
(On what the Seawolf heard)

It appears to have been a case of early-after-the-event-confusion with both surface
ships, the USS SEAWOLF, a nuclear submarine and the SEA OW, a diesel submarine
operating in the immediate area of the THRESHER event.

What was indisputable then and remains so now is the Sound Surveillance System
acoustic data which confirmed the THRESHER pressure-hull collapsed in less than
0.047 seconds at 09:18:24R or local time at the loss site, at a depth of 2400-feet,
almost twice THRESHER's "test depth" of 1300-feet. None of the crew survived
that event. Death was instantaneous; they never knew collapse was occurring

That acoustic signal was detected by 13 Sound Surveillance System hydrophone
arrays at ranges as great as 1300 nautical miles. Many of those hydrophone arrays
also detected reflections (echoes) of the collapse from the mid-Atlantic Ridge.
Nothing other than implosive collapse - the total destruction of the THRESHER
pressure-hull - could have produced an acoustic signal of that magnitude.

Bottom line: the acoustic data makes it indisputable that THRESHER was lost at
09:18:24R on 10 April 1963. Any assertion that the THRESHER crew survived beyond
that time has no basis in fact and amounts to an unfortunate and irresponsible
fiction.

Bruce Rule